Focussed ion beam lithography using a MeV proton beam microprobe for microoptics fabrication

Abstract

Deep, high-aspect ratio trenches have been fabricated in the resist Polymethyl methacrylate by exposure to a focussed beam of MeV protons followed by development. The depth of the trenches depends on the energy of the protons and simulations suggest that this can be up to 300 μm. The University of Melbourne Microprobe is capable of producing a focussed spot size of the order of a few microns. This opens up the possibility of fabricating extremely high-aspect ratio microstructures for use as optical components.